WO2023126240A1

WO2023126240A1 - Improved obstacle-crossing device for an electric wheelchair

Info

Publication number: WO2023126240A1
Application number: PCT/EP2022/086756
Authority: WO
Inventors: Michel Ohruh
Original assignee: New Live Ingenierie
Priority date: 2021-12-29
Filing date: 2022-12-19
Publication date: 2023-07-06

Abstract

The invention relates to an obstacle-crossing device for a motorized vehicle made up of a chassis (2), which is connected to three wheels (3a, 3b, 3c) on each lateral side of the chassis (2), and of motor means (5) designed to rotate the wheels (3a, 3b, 3c), and, on each lateral side of the chassis, there is a mechanism having two arms (7a, 7b) articulated in pairs about a common pivot axis (6), on which two arms (7a, 7b) are distributed the three wheels, respectively a front wheel (3a), an intermediate wheel (3b) and a rear wheel (3c), the mechanism allowing each wheel to pivot with respect to the axis of each adjacent wheel. The device is characterized in that the motor means (5) and the rear wheel (3c) are borne by an arm (10) articulated to the chassis (2) on a longitudinal member (14) via a pivot connection (13), the end (11) of the arm (10) that extends beyond the pivot connection (13) and on the opposite side to where the motor means (5) are secured cooperating with a slide (15) which is movable on the longitudinal member (14), the pivot connection (13) causing the front wheel (3a) to move between two end positions, namely a first position (20) in alignment with the other two wheels (3b, 3c) and a second position (21) which is lowered with respect to the alignment of the other two wheels (3b, 3c), the slide (15) having a wall (16) perpendicular to the sliding axis, whereas the longitudinal member (14) has a fixed wall (17) perpendicular to the sliding axis (22), at least one spring means (18) being interposed between the two walls (16, 17), whereas the arm (10) is dimensioned such that its free end (11) comes into contact with the wall (16) so as to push back the slide (15) while constraining the spring means (18) against the wall (16) when the front wheel (3a) is in its first position (20) aligned with the other two wheels (3b, 3c).

Description

Title of the invention: Improved crossing device for electric wheelchair

[0001] [The present invention relates to an obstacle crossing device for a motorized vehicle.

[0002] By motorized machine, we mean any machine whose purpose is to move independently, of the robot type, wheelchair, etc.

[0003] By way of example which will constitute the common thread of the present description, the motorized machine will more particularly concern a wheelchair.

[0004] This obstacle crossing device responds to current problems relating to the movement of people with reduced mobility (disabled or elderly) who use a wheelchair on a daily basis both indoors and outdoors.

In today's society, taking into account people with disabilities is a priority in urban planning projects, in the adaptability of housing, in access to roads and public or private transport.

[0006] Good accessibility determines social, educational and professional integration. Mobility and travel are the guarantee of daily and long-term quality of life.

[0007] For the freedom of movement to be real, the entire movement chain must meet the specific needs of people.

[0008] The first element of this movement chain is undeniably the wheelchair, which constitutes a technical aid for mobility by allowing a person to be transported without difficulty on a flat surface.

[0009] As urban planning projects take a long time to implement, on the order of a few years, the wheelchair must adapt to the current state of cities, roads, housing, etc.

[0010] However, roads have many sidewalks, shops often have a step, housing sometimes has a difference in level from room to room, etc. A wheelchair must be able to overcome these obstacles.

[0011] Many solutions have been proposed for this purpose. Among them, wheelchairs with six-wheel technology exist on the market. They have good maneuverability and good stability, but the crossing of obstacles is limited to low heights (less than 7.5cm) and this only with a sidewalk climbing option which acts as a lever to lift the front wheels.

[0012] Other 4x4 type wheelchairs exist and allow driving on any type of terrain (grass, gravel, stones) and overcoming obstacles of up to 15cm. The main drawback of these wheelchairs lies on the one hand in their imposing size preventing their use indoors and on the other hand in their lack of stability, because there is a risk of tipping forwards or backwards when crossing of obstacles.

[0013] We know, in particular, from the international application published under the number WO 2011/095753 an obstacle crossing device for a motorized vehicle consisting of:

[0014] - a frame connected to three wheels on each lateral side;

[0015] - motor means capable of rotating the wheels;

[0016] and, on each lateral side of the frame, there is a mechanism comprising two arms, articulated in pairs around a common pivot axis, on which the three wheels are distributed, respectively a front wheel, an intermediate wheel, and a rear wheel, said mechanism allowing each wheel to pivot relative to the axis of each adjacent wheel.

[0017] Said device is particular in that the frame is connected to each mechanism with articulated arms by means of two shafts mounted free in rotation, at least one of the shafts being capable of compensating for the variation in distance between these two trees when the arms are not aligned.

In other words, this device has the following particularity: the distance between two adjacent wheels is always fixed in order to avoid any collision between them. The wheels can move in height independently of each other others when they encounter an obstacle. Concretely, when the wheelchair is facing a sidewalk, the two front wheels will cross it first, while the other two wheels will remain in contact with the ground. Then the two following wheels will arrive facing the curb and will cross it, the other wheels remaining in contact with the ground. Eventually, the two rear wheels will clear the curb, with the front wheels remaining on the ground. At all times, the chair has more than three points of support so as to define a plane which gives stability to the chair.

[0019] As already mentioned, in the device described in this document WO 2011/095753 the frame is connected to each mechanism with articulated arms by means of two shafts mounted free in rotation, at least one of the shafts being able to compensate for the variation in distance between these two shafts when the arms are not aligned in a horizontal plane. Indeed, when crossing an obstacle, the wheels are not aligned, and the articulated arms pivot accordingly, thus forming an angle, resulting in a rapprochement of the two shafts. However, the frame of the chair has fixed dimensions and is connected to these two shafts. To avoid any deformation, or even breakage, of the chassis, it is therefore essential to be able to compensate for the modification of the center distance of the fixing shafts of the articulated arms with respect to the fixing center distance of these same shafts to the chassis, when crossing 'obstacles.

[0020] In general, such a device has the advantage of being able to offer people with reduced mobility a compact electric wheelchair to facilitate their daily movements, said wheelchair being in particular able to overcome obstacles up to 20 cm in height. and this in all forward angles of attack, without risk of tilting, thus making driving easier, especially for users who have difficulty in apprehending small obstacles.

[0021] Indeed, in particular, the wheelchair described in international application WO 2011/095753 can advantageously be provided with a front and/or rear anti-tilt device comprising, on each lateral side of the machine, means of blocking the pivoting of at least one articulated arm when tilting the frame forwards or backwards. [0022] In addition, this chair can also be supplemented by a device for assisting in crossing the rear of the machine, comprising on each lateral side of the machine, an anti-tipping wheel placed at the rear of the gear.

Another advantage of this wheelchair lies in the fact that it allows you to travel in the countryside on grass, gravel, stones, but also in snow and sand.

[0024] However, such an obstacle crossing assistance device for a motorized vehicle can still be improved.

[0025] In particular, improvements must be made in particular to avoid shocks and to better match the irregularities of the ground. It is in particular sought to improve the contact, the support, between the wheels, in particular the front and rear wheels, and the ground, in the case of crossing an obstacle, for example the ascent or descent of a curb.

[0026] To respond to these problems, and force the device to optimally match the unevenness of the ground, it was imagined to provide the crossing device with a return system which makes it possible to press the front and rear wheels against the ground level, in other words to force the device to make an angle so that said front or rear wheel is, in turn, forced to come into contact with the ground.

[0027] Note that, moreover, such a device also improves the traction of the front wheel in the particular case of climbing an obstacle and facilitates crossing the back of the wheelchair by lifting the wheel. back before it hits the obstacle.

To this end, the present invention relates more particularly to an obstacle crossing device for a motorized machine consisting of a frame connected to three wheels on each lateral side of said frame and motor means capable of rotating said wheels. and, on each lateral side of the frame, there is a mechanism comprising two arms, articulated in pairs around a common pivot axis, on which two arms are distributed over the three wheels, respectively a front wheel, an intermediate wheel and a rear wheel, said mechanism allowing each wheel to pivot relative to the axis of each adjacent wheel. [0029] Said obstacle clearance device according to the invention is particular in that the drive means and the rear wheel are carried by an arm articulated to the chassis on a spar, through a pivot connection, the end of the arm which extends beyond the pivot connection and on the side opposite to the attachment of the motor means cooperating with a movable slide on the spar, said pivot connection generating a movement of the rear wheel between two extreme positions, namely a first position in alignment with the two other wheels or a second position lowered with respect to the alignment of the two other wheels, said slide comprising a wall perpendicular to the axis of sliding while the spar comprises a fixed wall perpendicular to the sliding axis, at least one spring means being inserted between said two walls, while the arm is dimensioned so that its free end comes into contact with the wall so as to push back the slide while forcing the spring means against said wall, when said front wheel is in its first position aligned with the other two wheels.

According to particular embodiments of this crossing device:

[0031] - the support of the arm on the wall of the slide is done through a roller filling the end of said arm;

[0032] - two spring means are positioned between the walls of the slide;

[0033] - the motor means and the rear wheel are carried by the arm through a pivot connection;

[0034] - the device further comprises, on each lateral side, an anti-tip wheel placed at the rear of the motorized machine and fixed to the first end of said arm opposite the end coming into contact with the wall of the slide ;

[0035] - the device comprises a mechanical device for limiting the movement of the arm during the elevation of the seat, consisting of a movable stop under the action of the elevation of the seat;

[0036] - said frame being connected to each mechanism with articulated arms by means of two shafts mounted free in rotation, at least one of the two shafts being capable of compensating for the variation in distance between these two shafts when the arms do not are not aligned. Other objects and advantages of the present invention will appear during the description which will follow relating to embodiments which are given only by way of indicative and non-limiting examples.

The understanding of this description will be facilitated by referring to the attached drawings in which:

[0039] [Fig.1] is a schematic side view showing the wheelchair flat.

[0040] [Fig.2] schematically shows a partial view of the chair in section A-A.

schematically represent a sectional view of the improved obstacle crossing aid device according to the invention, in different positions, from a position where the wheels of the chair are flat, in Figure 3, to an obstacle crossing position, in Figure 6, passing through two intermediate positions in Figures 4 and 5, in order to illustrate the movement of said device and of the wheels when crossing an obstacle.

With reference to Figures 1 and 2 of the attached drawings, the present invention relates to an obstacle crossing device for a motorized vehicle consisting of:

- a frame 2 on which is fixed a chair 1, said frame 2 being connected to three wheels 3a, 3b, 3c on each lateral side;

- motor means 5 capable of rotating the wheels 3a, 3b, 3c.

On each lateral side of the frame 2, there is a mechanism comprising two arms 7a, 7b, articulated in pairs around a common pivot axis 6, on which are distributed the three wheels 3a, 3b, 3c, respectively :

[0046] - a front wheel 3a, positioned at the front of the first articulated arm 7a,

[0047] - an intermediate wheel 3b, positioned at the joint between the two arms 7a, 7b,

[0048] - and a rear wheel 3c, positioned at the rear of the second articulated arm 7b.

The two arms 7a, 7b are thus articulated around a common axis corresponding to the axis 6 of the intermediate wheel 3b. Said mechanism comprising the two arms 7a, 7b allows each wheel to pivot relative to the axis of each adjacent wheel.

The articulation between the two arms 7a, 7b therefore corresponds to a pivot connection. This allows the front 3a and rear 3c wheels to pivot around the axis 6 of the intermediate wheel 3b. The three wheels 3a, 3b, 3c can thus go up and down independently of each other when crossing an obstacle.

According to an advantageous characteristic of the crossing device of the invention, the frame 2 of the chair 1 is connected to each mechanism with articulated arms 7a, 7b via two shafts 8, 12 mounted free to rotate, at least one of the shafts being capable of compensating for the variation in distance between these two shafts 8, 12 when the arms 7a, 7b are not aligned.

According to a first variant, this condition can be fulfilled by a crankshaft type shaft composed of two cylindrical sections offset from each other. This offset compensates for the variation in distance between the two shafts when the wheels are not aligned.

[0054]According to a second variant, the crankshaft-type shaft may be composed of a first shaft section connected to an articulated arm and a second shaft section connected to the chassis, the two shaft sections being articulated between them by a connecting rod.

According to a third variant, this condition can be fulfilled by a horizontal sliding shaft between two stops defining the maximum and minimum distance authorized between the two shafts. This sliding shaft makes it possible to vary the distance between the two shafts at the level of the articulated arms or at the level of the chassis. For example, this sliding shaft can be introduced into a horizontal slot provided for this purpose in an articulated arm, or into a horizontal slot provided for this purpose on the frame.

[0056] Figure 2 reveals part of the electrical system located under the seat of the chair 1. There is a battery unit 4 connected on each lateral side to the front of the articulated arm mechanism 7a, 7b via a motor 5 and a motor shaft 8, and to the rear of the mechanism by a crankshaft type axis 12 mounted loose. The battery pack 4 is itself attached to the frame 2 of the chair. The axis of the crankshaft 12 preferably breaks down into two shafts 12a, 12b having their axes of rotation slightly offset relative to each other, in accordance with the first variant mentioned above, the first shaft 12a being integral with the chassis 2, in particular the battery block 4 while the second shaft 12b is integral with an articulated arm 7b.

Now, with reference to Figures 3 to 6, the obstacle clearance device for a motorized vehicle of the invention is particular in that the motor means 5 as well as the rear wheel 3c whose axis, referenced 3c ', is shown in said Figures 3 to 6, are carried by an arm 10. Note that the axes 3a' and 3b' of the front wheels 3a and intermediate 3b are also shown.

Said arm 10 is articulated to the frame 2, through a pivot connection 13, on a spar 14, in the form of a beam.

[0060] One of the ends of said arm 10, the end referenced 11 in the figures, which extends beyond said pivot connection 13, and on the side opposite to the connection of the motor means 5 and the rear wheel 3c on said arm 10, cooperates with a slide 15, which is movable on the spar 14.

[0061] In a particularly advantageous manner, said pivot connection 13 of the arm 10 on the spar 14 makes it possible to generate a movement of the front wheel 3a between two extreme positions that the latter can take, namely:

[0062] - a first position 20, shown in Figures 3 and 4 attached, in which said front wheel 3a is in alignment with the two other intermediate 3b and rear 3c wheels; note here that we are talking about an alignment of the three wheels 3a, 3b and 3c when said three wheels 3a, 3b and 3c are on a flat surface;

[0063] - a second position 21, shown in Figure 6, in which said front wheel 3a is no longer in alignment with the other two intermediate 3b and rear 3c wheels, but is lowered relative to a plane passing through the 'axis 3b' and 3c' of the intermediate 3b and rear 3c wheels.

Note that Figure 5 illustrates an intermediate position of the front wheel 3a, when the latter is moving from its first position 20, in which it is in alignment with the other two wheels 3b and 3c, to her second position 21, in which it is lowered relative to the two intermediate 3b and rear 3c wheels.

[0065] In addition, said slide 15 has a wall 16, perpendicular to the sliding axis, on which the end 11 of the arm 10 rests.

The spar 14 comprises, for its part, a fixed wall 17 which is also perpendicular to the sliding axis.

Between the wall 16 of the slide 15 and the wall 17 of the spar 14 is inserted at least one spring means 18.

Note that, preferably, two spring means 18 are positioned between the two walls 16 of the slide 15 and 17 of the spar 14 to balance the pressure and ensure perfect sliding of the slide 15.

[0069] The spring means 18 between the wall 16 of the slide 15 and the wall 17 of the spar 14 is put under tension when the approximation of said two walls 16, 17 to each other, when the front wheel 3a is located in its first position 20, in alignment with the two other intermediate 3b and rear 3a wheels.

For this purpose, the arm 10 is dimensioned so that its end 11 comes into contact with the wall 16 of the slide 15, so as to push back and move the latter, by constraining said at least one spring means 18.

[0071] According to an advantageous characteristic of the crossing device of the invention, the support of the arm 10 on the wall 16 of the slide 15 takes place through a roller 111.

[0072] The fact that the end 11 of the arm 10 is lined with a roller 111, which then rolls on the wall 16 of the slide 15, prevents the deterioration of said wall 16.

[0073] In addition, advantageously, the motor means 5 and the rear wheel 3c are carried by the arm 10 through a pivot connection 19.

[0074] Crossing an obstacle, climbing a sidewalk for example, takes place as follows:

[0075] - initially the three wheels 3a, 3b and 3c rest on the ground at the foot of the sidewalk and are aligned, [0076] - during the next step, the front wheel 3a goes up the sidewalk, the wheels 3a, 3b and 3c remaining aligned knowing that the intermediate wheel 3b is "in the air",

[0077] - during the next step, under the driving action of the front 3a and rear 3c wheels, the intermediate wheel 3b comes into contact with the sidewalk which has the effect of a load shedding which generates, under the effect of the relaxation of the spring means, the relative angulation of the arm 10 with respect to the beam 14, around the pivot connection 13, and consequently the elevation of the intermediate wheel 3b, thus preventing it from striking the edge of the sidewalk.

[0078] In a particularly preferential manner, the obstacle crossing device also comprises, on each lateral side and at the rear of the chair 1, an anti-tipper 9.

Each of said anti-tippers 9 with which the device of the invention is provided is fixed to the end of the arm 10 which is opposite the end 11 of the said arm 10 which comes into contact with the wall 16 of the slide 15.

[0080] The anti-tip rollers 9 also allow when crossing an obstacle such as a sidewalk, from a certain height, a temporary support grip as long as the rear wheel 3c has not come into contact with the sidewalk thus preventing it from hitting the edge of the sidewalk.

[0081] This obstacle crossing device also has, most preferably, a mechanical device for limiting the movement of the arm 10, when the seat 23 of the chair 1 is raised. This device for limiting the movement of the arm 10 consists of a mobile stop 22 that can be moved under the action of the elevation of the seat 23.

Such an elevation of the seat 24 is shown in particular in Figure 4, which clearly illustrates that said seat 24 is raised relative to the position it occupies in the other figures.

[0083] When the chair is in motion on ground that is horizontal or substantially horizontal, the weight of the assembly (user, chair, etc.) bears against the intermediate wheel 3b, the three wheels 3a, 3b and 3c are aligned, the end 11 of the arm 10 presses against the wall 16, resulting in a compression of the spring means(s) 18. In this configuration, shown in Figures 3 and 4 (Figure 4 illustrating a view in which the seat of the chair 1 has been raised relative to the view of Figure 3), the arm 10 carrying, on the rear with respect to the pivot link 13, the motor means 5 and the rear wheel 3c and also, preferably, at its rear end, the anti-tipper 9, is aligned, or substantially aligned, with the spar 14.

Still in this configuration, the end 11 of the arm presses against the wall 16 of the slide 15 which, by its movement, compresses the spring means 18, or the spring means 18 if necessary.

[0086] When crossing an obstacle, for example when the user of wheelchair 1 wishes to climb onto a sidewalk, or descend from a sidewalk, the weight of the assembly is no longer sufficient to align the wheels 3a, 3b and 3c.

[0087] Referring to Figures 5 and 6, the spring 18 then pushes the wall 16 and the slide 15, causing a pivoting of the arm 10 via the pivot connection 13, and a formation of the angle between the axes 3a', 3b' and 3c' of the three front wheels 3a, intermediate 3b, rear 3c and optimum support on the ground of the front wheel 3a in particular.

When descending a sidewalk, the thrust of the springs 18 prevents the rear wheel 3c from lifting and avoids the risk of the wheelchair tipping forward.

Claims

[Claim 1] [Obstacle crossing device for a motorized vehicle consisting of a frame (2) connected to three wheels (3a, 3b, 3c) on each lateral side of said frame (2) and motor means (5) suitable to rotate said wheels (3a, 3b, 3c) and, on each lateral side of the frame, there is a mechanism comprising two arms (7a, 7b), articulated in pairs around a common pivot axis (6), on which two arms (7a, 7b) are distributed the three wheels, respectively a front wheel (3a), an intermediate wheel (3b) and a rear wheel (3c), said mechanism allowing each wheel to pivot relative to the axis of each adjacent wheel, said device being characterized in that the motor means (5) and the rear wheel (3c) are carried by an arm (10) articulated to the frame (2) on a side member (14) through a pivot connection (13), the end (11) of said arm (10) which extends beyond the pivot connection (13) and on the side opposite to the connection of the motor means (5) cooperating with a slide ( 15) movable on the spar (14), said pivot connection (13) generating a movement of the front wheel (3a) between two extreme positions, namely a first position (20) in alignment with the two other wheels (3b , 3c) and a second position (21) lowered relative to the alignment of the other two wheels (3b, 3c), said slide (15) comprising a wall (16) perpendicular to the sliding axis while the spar ( 14) comprises a fixed wall (17) perpendicular to the sliding axis (22), at least one spring means (18) being interposed between said two walls (16,17), while the arm (10) is sized to that its free end (11) comes into contact with the wall (16) so as to push back the slide (15) while forcing the spring means (18) against said wall (16), when said front wheel (3a) is in its first position (20) aligned with the other two wheels (3b, 3c).

[Claim 2] Obstacle crossing device for motorized machine according to claim 1 characterized in that the support of the arm (10) on the wall (16) of the slide (15) is done through a roller ( 111) lining the end (11) of said arm (10).

[Claim 3] Obstacle crossing device for a motorized machine according to claim 1 or claim 2 characterized in that two spring means (18) are positioned between the walls (16, 17) of the slide (15).

[Claim 4] Obstacle crossing device for a motorized machine according to any one of claims 1 to 3 characterized in that the motor means (5) and the rear wheel (3c) are carried by the arm (10) through of a pivot link (19).

[Claim 5] Obstacle crossing device for a motorized machine according to any one of claims 1 to 4 characterized in that it further comprises, on each lateral side, an anti-tipper wheel (9) placed at the rear of the motorized vehicle and fixed to the first end of said arm (10) opposite the end (11) coming into contact with the wall (16) of the slide (15).

[Claim 6] Obstacle crossing device for a motorized vehicle according to claim 5, characterized in that it comprises a mechanical device for limiting the movement of the arm (10) when the seat (23) is raised, consisting a stop (22) movable under the action of the elevation of the seat (23).

[Claim 7] Obstacle crossing device for motorized machine according to any one of Claims 1 to 6, characterized in that the said frame (2) being connected to each mechanism with articulated arms (7a, 7b) via two shafts (8, 12) mounted free to rotate, at least one of the two shafts (12) being capable of compensating for the variation in distance between these two shafts (8, 12) when the arms are not aligned. ]